The Tunnel Under the World

The Tunnel Under the World original Italian title Il tunnel sotto il mondo is a 1969 lowbudget Italian sciencefiction film directed by Luigi Cozzi inspired by Frederik Pohls novel of the same name. It was the directorial debut of a 21yearold Luigi Cozzi. His work on this film brought him to the attention of famed horror film director Dario Argento and jump started his career.

Source: Wikipedia